Pulmonary Vascular Disease Flashcards
Which class of pulmonary HTN therapy is most likely to cause derranged LFTs?
Endothelin Receptor antagonists - Bosentan, Ambrisentan, Macitentan need monthly monitoring of LFTs
You see a 56-year-old woman in the clinic who is being treated for pulmonary hypertension. She reports feeling better and her activity levels have also improved but you notice a worsening of her leg oedema, which the patient is concerned about. The patient’s dose of her furosemide has been increased and her leg oedema is still getting worse. She is currently taking tadalafil and ambrisentan.
What should be done next to address her leg swelling?
Switch Ambrisentan to Macitentan
Leg oedema can be result of right heart failure from Pulmonary HTN and it’s a side effect of Ambrisentan therapy . Sx improving and oedema worsening despite furosemide so best option is to switch meds
What are the absolute contraindications to systemic fibrinolysis/ thrombolysis ?
- Hx of haemorrhagic stroke or stroke of unknown origin
- Ischaemic stroke within last 6/12
- CNS Neoplasm
- Major Trauma, surgery or head injury in last 3/52
- Bleeding diathesis
- Active bleeding
What are the relative contraindications to systemic fibrinolysis/ thrombolysis ?
- TIA in last 6 months
- Oral anticoagulant
- Pregnancy or 1 week post partum
- Non compressible puncture site
- Traumatic Resuscitation
- Refractory HTN ≥ 180
- Advanced liver disease
- Infective Endocarditis
- Active peptic ulcer
What set of follow up investigations required for stable PH?
The 2022 pulmonary hypertension guidelines specify a follow-up monitoring plan in case of a stable case of pulmonary hypertension (which is the case in this scenario). It recommends WHO-FC, a 6-minute walk test, ECG, ABGs or pulse oximetry, and bloods including NT pro-BNP be performed. RHC is more useful in the context of change in the treatment of worsening clinical symptoms.
What is the most common genetic abnormality in cases of heritable PAH?
Heterozygous mutations in the BMPR2 gene remain the most common genetic abnormality implicated in cases of heritable PAH, accounting for approximately 75% of hereditary cases. To date, a number of other genes also implicated in PAH have been identified, including ALK1 and endoglin. PAH patients with BMPR2 mutation are less likely to respond to vasodilator treatment, develop clinical manifestations of the disease at a younger age, and have more severe haemodynamics and a worse prognosis.
Lifetime pentrance 25% (thought a 2nd hit req)
What are common side effects of prostacyclin analogues ?
Headache and chest pain
GI discomfort and flushes
(Blurred vision and embolism very infrequent)
What is the definition of Pulmonary HTN?
An mPAP of >20mmHg at rest as assessed by aright heart catheterisation
How do you differentiate between pre and post capillary and combined ?
Pre Capillary Component :
PVR> 2 woods units (if severe will be >5WU)
Post capillary Component:
PVR ≤ 2 woods units
Combined Post and Pre Capillary PH: PVR >2 wood units
What are the 5 classes of pulmonary HTN?
I. Pulmonary Arterial Hypertension
II. PH associated with Left Heart Disease
III. PH associated with lung disease / hypoxia
IV. PH associated with pulmonary artery occlusion (CTEPH most common)
V. PH w unclear or multifactorial mechanism
What are the echo probabilities assigned?
TRV < 2.8 LOW
TRV 2.9 -3.4 INTERMEDIATE
TRV >3.4 HIGH
(NB if LOW but other signs , ie high PASP then becomes intermediate)
What is the gold standard investigation for diagnosis of PH?
Right heart catheter
What treatment is given for patients with PAH without cardiopulmonary co-morbidities and non vasoresponders who are low/intermediate risk?
Endothelin Receptor Antagonist (Ambrisentan , Macitentan, Bosentan)
AND
PDE5i
(Sildafenil, Tadalfil)
What treatment is given for patients with PAH without cardiopulmonary co-morbidities and non vasoresponders who are high risk?
Endothelin Receptor Antagonist (Ambrisentan , Macitentan, Bosentan)
AND
PDE5i
(Sildafenil, Tadalfil)
AND
Prostacyclin analogues
(Prostacyclin, epoprostenol, iloprost)
What model do we use to assess risk in PH follow up?
4 strata model
What model do we use to assess risk for PH initially ?
3 strata model
What is included in the 3 strata model risk assessment for PH?
Signs of RHF
Progression of sx
Syncope
WHO FC
6MWT
CPET
Biomarkers (BNP)
Echo
MRI
Haemodynamics
What is included in the 4 strata model risk assessment for PH?
WHO FC
6MWT
BNP/ NT-Pro BNP
If during follow up of low or intermediate patient not improving , what can we do?
- add prostacyclin receptor against (Selexipag)
- switch PDE5i to soluble guanylate cyclase stimulator (Riociguat)
If during follow found to be high or intermediate high what can we add in?
SC / IV prostacyclin analogue
Lung Transplant
What treatment is given for patients with PAH with cardiopulmonary co-morbidities and non vasoresponders ?
Endothelin Receptor Antagonist (Ambrisentan , Macitentan, Bosentan)
OR
PDE5i
(Sildafenil, Tadalfil)
What treatment can be used in PH associated with ILD?
Inhaled Trepostinil (procyclin analogue)
What dose mPAP of >20mmHg at right heart cath indicate?
Pulmonary HTN
What does PAWP > 15mmHg indicate ?
Likely PH assoc with LHD
What does PAWP <15mmHg indicate ?
Need to look at cardiac output
If Low /Normal: Pre- Capillary PH (ie PAH, PH - resp , CTEPH , multi factorial)
If high: Consider left to right shunt - look at O2 Sara if >90% then in keeping with L>R shunt
So what dynamics would you expect to see on RHC for PAH?
mPAP > 20 mmHg
PAWP ≤ 15mmHg
PVR > 2 WU
What vasoreactive agents do we use for vaasodilation testing ?
Inhaled Nitric Oxide
Inhaled Iloprost
IV epoprostenol
What is a positive vasoreactive test ?
Drop in mPAP of ≥ 10mmHg and to <40mmHg with increased or unchanged cardiac output
What is the gene associated with Pulmonary Veno-Occlusive disease ?
E1F2AK
What percentage of systemic sclerosis patients have PAH?
10%
Should have annual evaluation
What is the prevalence of PH ?
1% in the general population
What is the leading cause of PH globally ?
Left Heart Disease
What drugs/ toxins associated with PAH?
Aminorex (WL stimulant drug)
Benfluorex (appetite suppressant)
Dasatinib
Dexfenfluramine
Fenfluramine
Metamnephrines
Toxic Rapeseed oil
Some association with alkylation agents such as cyclophosphamide , amphetamines , cocaine , against Hep C
What is the cardinal early sx of PH ?
Dyspnoea on exertion
What is the first line non invasive diagnostic investigation for symptomatic PH?
Echo
What bloods are recommended in PH?
Routine biochemistry
Haematology
Immunology
HIV
TFTs
In PH what is WHO functional class 1?
Patient without limitation to physical activity
In PH what is WHO functional class 2?
Pt with slight limitation to physical activity , comfortable at rest
In PH what is WHO functional class 3?
Marked physical limitation to activity , comfortable at rest
In PH what is WHO functional class 4?
Pt w PH unable to carry out any physical activity without symptoms , symptomatic at rest
What is the estimated 1 year mortality for Low Risk PH?
<5%
What is the estimated 1 year mortality for Intermediate Risk PH?
5-20%
What is the estimated 1 year mortality for High Risk PH?
> 20%
When to perform RHC in PH?
At baseline
Repeats not usually helpful
What management recommended in PH in general?
Supervised exercise
Immunisations
Diuretics if RV failure
LTOT if PaO2 <8
Correct iron stores
In flight O2 <8 at sea level
Anticoagulation not usually recommended
Contraceptive advice if female and child bearing age
Are there teratogenic effects of PH meds ?
Endothelia Receptor Antagonist
Riociguat
What percentage of patients with PAH are vasoresponders ?
<10%
Does a favourable vasodilator response predict a favourable long term response to CCBs?
No
What CCBs are predominantly used in vasoreactive +ve PAH patients ?
Nifedipine
Diltiazem
Amlodipine
What are the indicators for referral to lung transplant ?
ERS/ESC High Risk or REVEAL score >10
Progressive hypoxaemia especially in PVOD or PCH
Progressive but not end stage liver / kidney dysfunction due to PAH or life threatening haemoptysis
What do you in PAH caused by drugs /toxins
Stop offending drug
Reassess once off for 3-4 months
If no improvement consider tx as per PAH
NB prev appetite suppressants and toxic rapeseed oil, today metamphetamines , interferons and some TKI
Who should be screened for PH?
Systemic sclerosis
Assessment of liver transplant
BMPR-2 mutation carriers
First degree relative of HPAH
What is the investigative work up for CTEPH?
VQ Scan and Echo
What is the treatment of CTEPH ?
Lifelong anticoagulation for all w VKA
If Operable: Pulmonary endarterectomy tx of choice
If not operable : Medical therapy with Riociguat
What are the risks for CTEPH?
Idiopathic PE
Increased Factor 8
Abnormality in fibrinogen
APL or lupus
Large clot burden
Splenectomy
Chronic inflammation
Hypothyroidism
Previous cancer
When do we use BPA in CTEPH?
For those who are inoperable or have residual PH after PEA and distal obstruction amenable to BPA
What kind of drug is Riociguat?
A stimulator of soluble Guanylate Cyclase
Who gets Riociguat in CTEPH?
Symptomatic patients with inoperable CTEPH or persistent / recurrent PH after PEA
How do we treat CTEPD - chronic thromboembolic disease (without Pulmonary HTN)
Long term anticoagulation
What causes Class V PH?
Haematological disorders
- Chronic Myelproliferative
- CML
- PV
- Idiopathic Myelofibrosis
- Essential thrombocytopenia
Inherited / Acquired chronic Haemolytic Anaemia:
- Sickle cell disease
- B thalassemia
- Spherocytosis
- AI disorders
Systemic:
- Sarcoidosis
- Pulmonary Langerhans Cell Histocytosos
- Neurofibromatosis Type 1
Metabolic
- Glycogen storage disorders
- Gauchers
Chronic Renal Failure with or without haemodialysis
Pulmonary tumour thrombotic microangiopathy
Fibrosing mediastinitis
What are the indicators that PE patient needs to be managed as an inpatient ?
- Haemodynamic instability (HR>110, SBP <100 , req inotropes , req thrombolysis)
- O2 sats <90%
- Active bleeding or major risk of bleeding (recent surgery , prev IC bleeding or uncontrolled HTN)
- On full dose anticoagulation at time of PE
- Severe pain (req opiates)
- Other medical co-morbidities
- CKD stage IV or V or severe liver disease
- HIT within last year and where no alternatives to repeating heparin treatment
- Social reasons
What are the WELLs cut offs for PE?
> 4 PE likely
<4 unlikely
What is included in WELLs for PE?
Clinical signs and symptoms of DVT (3)
An alternative dx less likely than PE (3)
HR >100 (1.5)
Immbolisation for >3 days or surgery last 4/52 (1.5)
Previous PE/DVT (1.5)
Haemoptysis (1)
Malignancy with treatment within 6/12 or palliative (1)
What do you do if WELLs score is > 4
CT-PA
Or
if allergic to contrast / severe renal impairment (eGFR <30) / high risk of irradiation assess suitability for VQ scan
What do you do if Wells score <4
D-Dimer
If +ve CT-PA
If -Ve think alternatives
What is the anticoagulation as per NICE for PE with no renal impairment, antiphospholipid or haemodynamic instability ?
Rivaroxaban or Apixaban
What is treatment for CrCl 15-50 with PE?
Apixaban
Rivaroxaban
LMWH for at least 5/7 then Dabigatran /Edoxaban
What is treatment for CrCl <15 with PE?
LMWH
UFH
What is treatment for PE with cancer ?
Consider DOAC
LMWH
LMWH and VKA
What is treatment for PE with Antiphospholipid ?
LMWH (for at least 5/7 or until INR at least 2 on 2 consecutive readings) and VKA
What are the extremes of body weight where modifications req in PE tx ?
<50kg
> 120 kg
In patients who decline anticoagulation with PE what can be given to them ?
Aspirin
What is the risk of VQ scan in pregnant women?
Slight increase of childhood cancer but associated with reduced risk of maternal breast cancer
What is the risk of CT-PA in pregnant women?
Slight increase in risk of maternal breast cancer
What dose of tx dose enoxaparin do you give pregnant women?
Titrate to women’s booking or early pregnancy weight
What is maintenance tx of VTE in pregnancy?
LMWH for remainder of pregnancy and at least 6/52 post partum and until 3/12 has been given
What treatment for PE at term?
Consider UFH as more easily manipulated
If planning C-Section when should LMWH be held?
24 hours prior
How long until you give LMWH after spinal anaesthesia/ epidural removal?
4 hours
How much higher is the risk of antenatal VTE?
4-5x higher
When is the highest risk of VTE in pregnancy?
Puerperium (6 weeks after childbirth) - x20 fold higher
If collapses with PE when pregnant
CPR in left lateral tilt
Perimortem c-section if >20 weeks
IV UFH 80 units/kg loading followed by 18 units /kg/ hr and measure APTT
Are heparin (unfracrtionated or LMWH) or warfarin contraindicated when breastfeeding ?
No
When is VTE risk in adult life at its highest ?
5th decade ; x8 higher
What are the predisposing risk factors for PE?
- Major trauma, surgery, lower limb #, joint replacement, SCI
- Cancer - particularly pancreatic , haematological , lung , gastric and brain
- Oestrogen containing OCP most freq risk factor in women of reproductive age (COCP incr risk by 2-6 x, third generation COCP higher risk than second)
- Infection is a common trigger
What is the primary cause of death from PE?
RV failure due to acute pressure overload
What can PERC be used as ?
A rule out test developed to identify patients with very low risk of having PE
Age <50, HR<100 , Sats>94%, No unilateral leg swelling, no haemotysis, no recent trauma , no hx of VTE, no hormone use
What is the value of D-Dimer ?
It has a high negative predictive value
At what age do we age adjust the D-Dimer ?
> 50
In acute PE what are the echo findings most commonly associate with poor outcome ?
RV/LV ratio ≥ 1
TAPSE <16mm
What are the lab biomarkers of increased risk?
Trop/ BNP
Lactate ≥ 2
Elevated creatinine
What is included in the simplified PESI?
Age >80
Cancer
Chronic Heart/Lung
HR>110
BP <100
Sats <90
What does s-PESI and PESI identify?
30 day mortality
What is included in the PESI score ?
Age, male, cancer , CHF, Chronic pulmonary disease , HR ≥110 , BP <100 , RR> 30 , T <36 , Altered mental state , PaO2 <90%
PESI is the most extensively validated score and its principle strength is identifying those at low risk of 30/7 mortality
What is the risk with s-PESI 0 in PE?
1%
What is the risk with s-PESI 1 or greater than 1 in PE?
10%
What is a low risk PE as per PESi / s-PESI?
PESI Class 1 or 2
sPESI 0
Why do PE patients get hypoxic ?
VQ mismatch
How long should CPR continue post thrombolysis for PE?
1 hour
What is the primary pathology of vasculitis ?
Inflammation and necrosis of differing sized blood vessels
Why do you get alveolar haemorrhage in vasculitis ?
Neutrophilic infiltration and subsequent fibrinoid necrosis causes vessel wall destruction and interstitial capillaries are injured allowing RBCs to enter the alveoli causing alveolar damage
What ANCA is anti-PR3 associated with?
Assoc with c-ANCA
What ANCA is anti-MPO associated with ?
Assoc with p-ANCA
What is granulomatosis with polyangiitis (GPA) ? (Prev termed Wegner’s)
Necrotising vasculitis affecting small and medium vessels especially the upper and lower respiratory tract and the kidneys associated with granulomas
Who gets GPA?
Unknown cause
40-55 years
Male:Female
80-97% Caucasian
What are the clinical features of GPA?
ENT- 90% upper airways involvement. Nasal congestion & epistaxis , inflamed , crusty , ulcerated nasal mucosa- late sign is saddle nose deformity. Sinusitis is common, otitis media , subglottic stenosis causing upper airway obstruction , dyspnoea, voice change and cough - abnormal Lung function
Lung: affects 85-90% ; haemoptysis , cough and dyspnoea w pleuritic chest pain
Kidney: affected in 77%, haematurea , proteinurea with red cell casts (only 10 % have renal involvement initially , but 80% will have during disease course) . Characteristically progressive deterioration in renal function
Systemic: fever and weight loss
Other: skin, joints , eyes , CNS
What does chest imaging show in GPA?
Flitting cavitatory pulmonary nodules, consolidation or pulmonary infiltrates , alveolar haemorrhage , parenchymal distortion, distal large and small airway disease , pleural effusion and bronchiectasis
Can look like neoplasm, infection, fluid overload
Pulm Haemorrhage, Cavities , Reticulation , Wedge Infarct
What bloods for GPA?
FBC, U&E , CRP, ESR
ANCA- particularly c-ANCA (Anti PR3) sensitive and fairly specific , cANCA present in 90% of patients with extensive GPA; 75% in limited HOWEVER p-ANCA positive in 5-10%
ALSO
ANCA can be -ve especially if confined to respiratory tract
What will you be looking for on urine microscopy in GPA?
Red cell casts
What might bronchoscopy show in GPA?
Inflammation and ulceration of the larynx, trachea and bronchi. Scarring and stenosis may be seen. BAL neutrophilic + eosinophils + lymphocytes
What will you see on biopsy of resp tract /Nose in GPA?
Granulomata associated with medium and small vessel necrotising vasculitis and surrounding inflammation
NB nasal biopsies often non specific
What will see on renal biopsy in GPA?
Focal segmental or diffuse necrotising glomerulonephritis. Not specific for GPA. Pauci immune and granulomata are rare
How do we diagnose GPA?
Biopsy and ANCA (high anti PR3 strongly suggestive of GPA)
How do we treat life threatening GPA?
Plasma exchange (7 x 4L over 2 weeks)
PLUS
Methylprednisolone and Cyclophosphamide (can use Rituximab as alternative)
Dialysis for renal failure
How do we treat generalised or organ threatening GPA?
Induction with Prednisolone and Cyclophosphamide
Maintenance with Prednisolone and AZT/MTX
How do we treat localised disease or early systemic disease (without threatened organ involvement) in GPA?
Prednisolone with either MTX or oral/pulsed cyclophosphamide
What is the risk of relapse with GPA?
50%
What is the aim of treatment with GPA?
Aim is to reduce irreversible tissue necrosis. Evidence that regime induction gives remission of 80% of patients at 3/12 and 90% at 6/12
How long do we continue maintenance therapy for GPA and what is it ?
24 months
Pred + AZT /MMF
(Some recommend upto 5 years if ANCA still positive)
Does ANCA predict relapse in GPA?
No rising ANCA titres are a poor predictor of relapse without other features however removing immunosuppression in context of high ANCA is assoc with relapse
What type of involvement has the best prognosis in GPA?
Limited with pulmonary but no renal
Involvement and c-ANCA -ve
What is the mortality of GPA?
Untreated 80% would die in one year
What is microscopic polyangitis ?
Small vessel vasculitis, at least as common as GPA and difficult to distinguish , managed in same way
Who gets microscopic polyangitis ?
Male:Female
Mean age 50
Mainly Caucasian
What organs are effected in microscopic polyangitis ?
KIDNEYS- main organ affected - proteinurea and haematurea ; normal biopsy shows focal segmental glomerulonephritis with fibrinoid necrosis and sparse immune deposits
PULMONARY- 30-50% , pleurisy , asthma , haemoptysis , pulmonary haemorrhage
What ANCA is microscopic polyangiitis associated with ?
Assoc with p-ANCA but also c-ANCA
How do you treat microscopic polyangiitis?
Steroids and cyclophosphamide (Rituxumab can be used)
What is Anti GBM (Goodpastures) disease ?
Linear deposits of IgG on the basement membrane of alveolar and glomeruli causing damage to collagen and in the lung allowing leakage of blood
Who gets Anti GBM (Goodpastures) disease?
Male 4 : Female 1
20-30 yo (NB 2nd peak for women in late 60s affected by glomerulonephritis alone)
Often preceded by a viral infection
** smokers at greatest risk of pulmonary haemorrhage (not anti GBM disease)
HLA-DR2 in 60-70%
What are the clinical features of anti GBM disease ?
Haemoptysis 80-90% (more common in smokers)
Cough , dyspnoea, fatigue, inspiratoru crackles
Hallmark; Anti GBM antibodies in blood , alveolar haemorrhage and glomerulonephritis
What does imaging show in Anti GBM disease ?
Diffuse patchy airspace shadowing in mid and lowe zone
What do PFTs show in anti GBM disease ?
Restrictive pattern
Raises KCO if alveolar haemorrhage
How do we diagnose anti GBM disease ?
Renal Biopsy - crescenteric glomerulonephritis - linear IgG deposition detected by immunofluorescence or immune peroxidase
Lung biopsy - active intra alveolar haemorrhage either collections of haemosiderin laden macrophages
How do we manage anti GBM disease ?
PLEX - improves response to immunosuppression
High dose steroids and Cyclophosphamide
May need dialysis and NB renal function may not improve , may need transplant if anti GBM antibodies become low
What is prognosis of Anti GBM disease if not treated ?
Fatal
Who gets eosinophilic granulomatosis with polyangiitis ?
Rare
Middle aged
Male 2: Female 1
Unknown cause
Asthmatics !
What do you need to have to have diagnosis of EGPA?
Need to have 4 out of the 6 of :
- Asthma
- Eosinophils >10%
- Vasculitic neuropathy (Mononeuritis multiplex)
- Pulmonary infiltrates
- Sinus disease
- Extravascular eosinophils on biopsy
What are other features you may see in EGPA bar the classical definition ?
Myositis / Cardiac failure, Cardiomyopathy , coronary artery inflammation, pericardial inflammation
Eosinophilic infiltration of mesentery vessels causing GI disturbance
Alveolar haemorrhage
Rarely renal disease
Skin nodules and purpura
Myalgia and arthralgia
Fever and WL
What are the 3 phases of EGPA?
Asthma > Blood and tissue eosinophilia > systemic vasculitis
What are the imaging findings of EGPA?
HRCT: Ground glass inflammation, pulmonary nodules , bronchial wall thickening , alveolar haemorrhage
CXR: fleeting pulmonary infiltrates and bilateral multi focal consolidation
What are findings of EGPA on bronch?
Marked eosinophilia
What do you find at biopsy for EGPA?
Extravascular eosinophils , necrotising angiitis and granulomata
What do bloods show in EGPA ANCA wise ?
Assoc with p-ANCA positive (anti MPO) in 2/3
NB ANCA levels may not correlate with disease activity
How do you diagnose EGPA?
Predominantly clinical ; pathological confirmation of eosinophilic tissue infiltration or vasculitis desirable , biopsy easiest site affected
How do you we manage EGPA with isolated pulmonary disease ?
Prednisolone
How do we manage EGPA if alveolar haemorrhage / generally unwell with it ?
IV Methylpred followed by high dose steroids
How do we manage EGPA if cardiac /GI / relapse / life threatening
IV methylpred and IV Cyclophosphamide
No benefit of PLEX in EGPA
What is maintenance for EGPA?
Prednisolone and another immunosuppressant , usually cyclophosphamide
What is the prognosis like in EGPA?
Good if isolated pulmonary disease (nb may continue to have poorly controlled asthma even after treatment)
Poor if cardiac or GI involvement
What is poly arthritis nodosa associated with ?
Preg Hep B and Hep C (rarer)
Rare to have lung involvement
Can overlap with GPA/EGPA
Affects medium vessels
What is Takayasu Arteriitis ?
Large vessel vasculitis
Affects young , Asian patients
Vasculitis affecting the aorta and its major branches , large and medium sized , can affect pulmonary vessels but involvement is usually silent . Pulmonary artery stenosis and occlusion common occasionally with mild pulmonary HTN
Patients have fever and WL with absent /weak peripheral pulses
Dx: Angiography
Tx: Steroids reduce sx but don’t affect mortality may need angioplasty /surgery
What is GCA?
Large vessel vasculitis
Sx: Fever, WL , headache, scalp tenderness, amaurosos fugax due to optic neuritis
Dx: High ESR, temporal artery biopsy
Tx: Steroids
What is the classical lesion in PH?
Plexiform lesions - disorganised proliferation of endothelial cells to form a capillary like plexus of channels. These are often located at arterial branching points
What are colander lesions?
Associated with CTEPH, small areas of re-canalisation in organised thrombus
What are the worrying fx indicating need for I&V in GBS?
FVC <15ml/kg
Hypercapnia
Hypoxia
(NB 40% GBS patients will have resp muscle weakness , 30% may require ICU)
Bulbar dysfunction or facial weakness herald issues
What is the 5 year survival for COPD pt with mPAP > 40
15%
What are PAVMs?
Structurally abnormal vascular communication that provides continuous right to left shunt between pulmonary arteries and veins
PAVMs allow a proportion of the RV stroke volume to bypass gas exchange , filtration and other functions of the capillary bed
NB patients will demonstrate platypnoea orthodeoxia
Why do we worry about PAVMs?
1 in 4 will have a paradoxical embolic stroke /abscess / MI
1 in 100 women in pregnancy get life threatening haemorrhage
What are majority of PAVMs due to?
HHT (Autosomal dominant ; 50% of patients with HHT have CT detectable PAVMs )
What do PAVMs cause ?
Ischaemic strokes
MI
Cerebral/ Peripheral abscesses /discitis
Do PAVMs need treatment ?
Yes, regardless of size / symptoms all patients should have PAVM embolisation if no c/i
What are the relative contraindications to embolisation of PAVM?
Pregnancy
PH
Renal impairment
Should PAVM patients get LTOT?
Despite oxygenation parameters that would fulfil criteria for supplementary O2 in other clinical settings , patients with hypoxaemia due to PAVMs display good exercise capacity, flight tolerance and good prognosis.
No indication for supplementary O2 , bed rest or exercise limitation for asymptomatic hypoxic pt with AVM
Remember: there is no alveolar hypoxia in patients with PAVMs
Outline ischaemic stroke in PAVM
PAVM incr risk
Can be managed with anti platelet agents but safety of thromvolysis is not established
Do PAVM need prophylactic abx prior to procedures ?
YES prophylactic abx prior to dental, endoscopic , surgical or other procedures
Judicial dental hygiene needed
Outline PAVM in pregnancy
PAVMs can increase in size
Majority proceed normally but 1% risk of maternal death
Ideally should be treated prior to conception
Who should get screened for PAVMs?
All patients with >16 with known/ suspected HHT should be screened
Normal sats and CXR do not exclude , contrast or non con CT req ; +Ve CT is diagnostic , contrast echo can be positive for other reasons , so CT is key
What are genes associated with HHT?
ENG
ACVRL1
SMAD 4
Who requires inpatient management for PE
- Haemodynamic instability HR >110 , SBP <100 , req inotropes or theombolysis
- O2 sats < 90%
- active bleeding or major risk of bleeding
- on full dose anti coag at time of PE
- severe pain (req opioids)
- other medical co- morbidities
- CKD stage 4 or 5 or liver disease
- HIT within last year
- Social reasons
PESI greater than or equal to 48
Or sPESI >0
What is the primary cause of death in PE?
RV failure due to acute pressure overload
Is D-Dimer useful in ?PE
Has a high negative predictive value but low positive predictive value
Over 50 should use age adjusted
What percentage of PEs originate from DVT in lower limb?
70%
What are the echo findings in acute PE most commonly associated with poor outcome ?
RV/LV ratio ≥ 1
TAPSE <16
What is TAPSE
Tricuspid annular plane systolic excursion (TAPSE) is measured as the displacement of the lateral tricuspid annulus toward the apex during systole.
Outline DOACs MoA
Dabigatran : Inhibits thrombin
Apixaban, Edoxaban , Rivaroxaban : Anti Xa
When is greater benefit of thrombolysis (for those who need)
Initiation within 48 hours of onset but can still be used upto 6-14 days
Aim is for significant reduction in haemodynamic decompensation /collapse
What are the indications for IVC filter?
- VTE and absolute contraindication to anticoag
- recurrent PE despite anti coag
-high risk PE
For patients with cancer what anticoagulation do we use in PE?
LMWH by weight
Can use EDOXABAN or RIVAROXABAN patients without GI cancer
What is CTEPH?
Chronic Thrombo Embolic Pulmonary HTN caused by the persistent obstruction of pulmonary arteries by organised thrombi leading to flow redistribution and secondary remodelling of the microvascular bed
How diagnose CTEPH ?
RHC showing mPAP > 20 and PAWP less than or equal to 15
In a patient with mismatch perfusion defects on CT
What are the indications for thrombolysis ?
Cardiac arrest
Obstructive shock: SBP <90 or vasopressers required to achiever BP ≥ 90mmHg
Persistent Hypotension : SBP <90 or systolic drop ≥ 40mmHg lasting longer than 15 mins
How do we estimate mPAP on echo?
(0.61 x PASP) + 2
What is platypnoea orthodeoxia?
Platypnoea is breathlessness when changing from recumbent to upright position and Orthodeoxia is fall in sats when changing from recumbent to upright position
Outline utility of VQ
High negative predictive value
